Wind bags which would store excess energy from wind turbines as compressed air under the sea are being tested by a Nottingham University professor.
Seamus Garvey's idea to hold air in bags the size of 10 double-decker buses, compressed by the sea, has been backed by E.On.
The power company has invested £236,000 towards building two prototypes, which are now being tested in 15-tonne tanks.
Mr Garvey said more storage of renewable energy was needed.
'Like bicycle tyres'
Once tests have been conducted on the scaled-down wind bags in Mr Garvey's laboratory at the university, the next step is to try them out in the sea.
Seamus Garvey has built wind bag prototypes
Mr Garvey said currently energy from wind turbines has to be used when it is created, or lost.
Using his invention, excess energy would be used to compress and pump air into underwater bags, anchored to the seabed.
When energy demand is highest the air would be released through a turbine, converting it to electricity.
Mr Garvey said: "These are like huge bicycle tyres under the sea where we are not just interested in putting the energy in, we have a way of getting it back out."
He added that as the world moved towards using more renewable energy, storage was going to be crucial to avoid waste.
The government is committed to providing 15% of all its energy from renewables by 2020.